Variable-stroke pump for hydraulic speed-gears.



C. M. MANLY. VARIABLE STROKE PUMP FOR HYDRAULIC SPEED GEARS;

APPLICATION FILED JUNE 29,19I4.

Patented 001;. 29, I918,

2 SHEETS-SHEET 1.

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APPLICATION FILED lUNE 29,19l4.

Patented Oct. 29, 1918.

2 SHEETSSHEET 2 B in X at.

CHARLES M. MANLY, 0F FREEPORT, YORK.

, VARIABLE-STROKE PUMP FOR HYDRAULIC SPEED-GEARS.

example as described in my prior Patents No. 1,212,791, granted January16, 1917, and

No. 1,206,453, granted November 28-, 1916.

This invention has for its object to improve stroke adjusting mechanismof the pumps disclosed in said applications, to render it simpler inconstruction, cheaper to manufacture, more efficient in operation, andless liable to leakage of fluid than the adjusting mechanism illustratedin the prior applications. 1

With the above objects in view my invention consists of the constructionhereinafter described and shown in the accompanying drawings, in whichFigure 1 is a horizontal sectional view along the shaft line of thepump, and Fig. 2 is a horizontal section on a plane above the shaft ofthe pump and showing the connections for the adjusting fluid.

Referring now to the drawings, and particularly Fig. 1, 1 indicates thecrank casing in which is suitably supported the main crank shaft 2 foroperating the pistons of 1 the radial pump cylinders 3 of which thereare preferably five, although the number may be varied more or less asdesired. The

crank shaft 2 has a fixed crank pin 4 and pump pistons, while in theopposite position of adjustment it will give the pump pistons theirmaximum stroke equal to twice the stroke which would be effected by thecrank pin alone. At any intermediate position of adjustment the pumppistons will obviously have a corresponding partial stroke.

As in my prior applications, I provide a fluid pressure operatedmechanism for ad justing the eccentric bushing aroundvthe crank pin.This mechanism comprises a sleeve 6 surrounding-the shaft 2 and havingSpecification of Letters Patent.

Application filed June 29, 1914.

-ing adjustment of the pump stroke.

Patented (Bot. 29, 1918.

Serial No. 847,971.

at its end an internal gear 7 meshing with a pinion formed integral withthe bushing 5. Within the supporting bearing 8 a bushing is interposedbetween the shaft and the sleeve to properly support the shaft, andbeyond the bearing the shaft is threaded as indicated at 9 for thereception of a nut 10 working on the thread between shaft 2 and thesleeve which is provided with longitudi- 'nal slots 11 throughout thelength of the tread. Attached to the nut and working'in the slots of thesleeve are shoes 12 which are carried by a ring 13 having a flangearound its middle which is inclosed in a suitable yoke 14. Ball bearings13 are inten posed between the flange of the ring 13 and the inturnedend flanges of the yoke 14, whereby the yoke maybe held against rotationand adjusted longitudinally of the shaft, thereby producing a relativerotation of the sleeve and the shaft with correspond- The nut 10, thering 13 and interposed shoes 12 are all connected together by radialpins 13 set in the middle flange of the ring 13 at points correspondingwith the position of each shoe and projecting through the ring 13 andthrough the shoes 12 and into the'nuts 10 so that the parts all movetogether upon the reciprocation of the yoke.

The mechanism so far described is substantially the same as that shownin my prior applications. My present invention has to do specificallywith the mechanism for adjusting the yoke longitudinally of the shaft.As shown the yoke is provided with a central annular part inclosing theshaft and the ring 13 and at each sideit is provided with integralannular ears 15 of a smaller diameter than the central part. The yoke ispreferably formed of similar longitudinal halves whereby it may beclamped over the central ring 13 as shown in Fig. 1.

Set in the ears 15 are adjusting cylinders 16 whose open ends face thecrank casing 1. The cylinders are held in place by means of collars 17formed on the cylinders adjacent their open ends and clamped in thegroove between the two halves of the yokeas shown in the drawing. Withinthe cylinders 14: are pistons 18 fixedly attached to hollow piston rods19.

The open .ends of the cylinders 16 are closed by suitable caps 20. whichsurround the piston rods 19 and have a fluid-tight fit therewith. Thepiston 18 is recessed on its the cap of the cylinder. To provide a fluidconnection with the opposite side of the piston a tube 21 preferably ofsteel and of smaller diameter than the bore of the rod 19 is inclosed inthe bore and connects through the'hollow end of the piston rod with theclosed end of the cylinder. The fluid is admitted to the cylinderbetweenthe cap and piston through transverse bores 22 in the piston rod.

The adjusting fluid is delivered to th piston rod 19 and the inner tube21 through the medium of a control valve mechanism, which will now bedescribed. As shown in Fig. 2 the adjusting mechanism is inclosed in acasing 23 which is rigidly bolted to a flange 24 formed on the adjacentend of the crank chamber 1. The casing 23 is provided with a transverseweb 25, a portion of which is shown in Fig. 2 and extendinglongitudinally and central of this web is a valve chamber 26 in which ismounted the control valve 27 similar in all essential respects to thecontrol valve employed in my prior applications. Connecting with themiddle of the valve chamber 26 is a passage 28 which is connected with asuitable source of fluid under pressure, not shown. Also connecting withthe valve chamber 26 near the ends thereof are passages 29, 29 whichconnect with a suitable exhaust chamber or other fluid circuit of lowpressure. Between the passa e 28 and the passages 29, 29*, the

venience as on the same plane, but it is to I he understood, however,that the passages 30, 31, are on a level slightly lower than theothertwo passages to permit the passage 31 to cross beneath the otherpassage. The passages 31, 31 terminate at each end in vertical bores inthe crank chamber casting, the bores of the passage 31 connecting withthe seat of the inner tube 21, while the bores at the ends of thepassage 31 connect with cavities 32' surrounding the tube 21 and formingseats for the piston rods 19. In thismanner the portion of the valvechamber 26 on one side of the middle high pressure passage 28 is at alltimes connected with the adjusting cylinders on one side of the pistons18, while the other side of the piston is at all times connected withthe opposite end of the valve chamber The valve 27 which controls theadmission of fluid to the adjusting cylinders is provided with a middlehead 33 of a width to exactly close the passage 28 and with heads 34, 34which when the passage 28 is closed out off the passages 29, 29 fromconnection with the passages 30, 30. When the valve is adjusted ineither direction from the central neutral position just described andshown, the passage 28 will be connected with one of the passages 30, 30"to admit fluid under pressure to one side of the adjusting cylinderswhile the other of the passages 30, 30 will be connected to one or theother of the exhaust passages 29, 29 to receive the fluid forced out ofthe other side of the adjusting cylinders.

For operating the valve 27 I preferably provide a floating lever 35connected at its middle point to the valve and provided at one-end witha rod or other suitable connection for manual operation. The other endof the lever is connected through a link 36 with the yoke 14. When therod is operated to shift the valve the lever will turn on its connectionwith the yoke as a fulcrum and open the valve to an extent de terminedby the extent of its movement. When the fluid under pressure passes intothe cylinders as described, the yoke will be shifted in the oppositedirection to the movement of the rod, thereby closing the valve andstopping the yoke after it is moved through a distance proportional tothe movement of the rod. In this way the position of the rod exactlydetermines the position of the yoke and consequently the relativepositions of the eccentric and the crank pin which determines the strokeof the pump.

An impotant advantage of my present invention is the construction andarrangement of the parts to provide fluid-tight connections at all thejoints in the passage of the adjusting fluid. As explained in my priorapplications the fluid in a hydraulic transmission is sometimes undervery high pressure and. cannot be held satisfactorily by ordinary packedjoints. The piston rods 19 are connected with the flange 24 of the crankchamber casting to have fluid connection with the chambers 32 by meansof tapered extensions 10 formed on the ends of the piston rods andfitting correspondingly tapered seats in the casting. The extensions 40are thin enough to be slightly compressed by the pressure which can beexerted on the clamping bolts 41. This joint is tight under anypressureof fluid for the reason that the pressure'of fluid on the inside of theextension will expand the metal against its seat with a forceproportional to the pres sure of the fluid. In like manner the innertubes 21 are tapered at each end and seated in correspondinglytapered'sockets in the piston rod and casting respectively. These jointswill obviously be drawn tight by the that all the joints and passagesfrom thevalve to the adjusting cylinders are in the casing 23 where thefluid will be collected I and returned through the circuit heretoforedescribed in the prior applications.

A further feature of advantage of my improved mechanism is that theparts may be made much lighter than heretofore possible. The reactionfrom the adjusting force is taken up by the crank chamber, therebypermitting a lighter casing 23 to be employed and without requiring acomplicated casting for the crank casing.

Having thus described my invention, what I claim and desire to secure byLetters Patent is j 1. In a fluid pressure operated adjusting mechanismof the class described, the combination of a rotatable shaft having avariable stroke crank, a crank case inclosing said crank, said shaftprojecting beyond the end of said case, a member to be adjusted on theprojecting portion of said shaft for efiecting the adjustment of saidcrank, the end of said casing constituting a fixed abutment member, aclosed cylinder attached to said adjustable member, a piston in saidcylinder and fixedly connected to said abutment member, and means forsupplying fluid under pressure to the opposite sides of said pistonwithin said cylinder.

2. Ina fluid pressure operated adjusting mechanism of the classdescribed, the combi nation of a rotatable shaft having a variablestroke crank, a crank case inclosing said crank, said shaft projectingbeyond the end of said case, a member to be adjusted on the projectingportion of said shaft for effecting the adjustment of said crank, theend of said casing constituting a fixed abutment member, a closedcylinder attached to said adjustable member, a piston in said cylinder,a hollow piston rod connecting said piston to said abutment member andmeans for transmitting the fluid under pressure through said piston rodto the opposite sides of said piston in said cylinder.

3. In afluid pressure operated adjusting mechanism, of the classdescribed, the combination of a rotatable shaft having a variable strokecrank, a crank case inclosing said crank, said shaft projecting beyondthe end of said case, a member to be adjusted on the projecting portionof said shaft for effecting the adjustment of said crank, the end ofsaid casing constituting a fixed abutment member, a closed cylinderattached to said adjustable member, a piston insaid cylinder, a hollowpiston rod connecting said piston to said abutment member, said pistonrod being formed with two separate fluid passages, and means fortransmitting fluid under pressure through said separate passages to theopposite sides of said piston in said cylinder.

4:. In a device of the class described, the combination of a rotatableshaft having a variable stroke crank, means for adjusting said crankcomprising a member adjustable longitudinally of said shaft, a pluralityof cylinders attached to said member on opposite sides thereof andextending parallel with said shaft, a casing for said shaft comprising acrank case having shaft bearings with theshaft projecting beyond the endwall of said crank case, and an inclosing cas-. ing surrounding theprojecting portion of said shaft, a plurality of stationary pistonsattached to said end wall and working in said cylinders and means fordelivering fluid under pressure to said cylinders behind said pistons.v,

In a device of the class described, the combination of a rotatable shafthaving a variable stroke crank, means for adjusting said crankcomprising a member adjustable longitudinally of said shaft, a pluralityof cylinders attached to said member ori opposite sides thereof andextending parallel with said shaft, a casing for said shaft comprising acrank case having shaft bearings with the shaft projecting beyond theend wall of said crank case, and an inclosing casing surrounding theprojecting portion of said shaft, a plurality of stationary pistons at:tached to said end wall and working in said cylinders and means fordelivering fluid under pressure to said cylinders behind said pistons,said means comprising a valve in said casing, and passages formed in theWall of the casing and through said piston rods.

6. In a device of the class described, the combination of a rotatableshaft having a variable stroke crank, means for adjusting said crankcomprising a member adjustable longitudinally of said shaft, a pluralityof cylinders attached to said member on opposite sides thereof andextending parallel member, a casing inclosing said mechanism and saidmember comprising a crank case Having shaft bearings with the shaftprojecting beyond the end wall of said crank case, and an inclosing'casing surrounding the projecting portion of said shaft, an adjustingcylinder attached to said member, said cylinder being closed at eachend, a pis ton in said cylinder, a hollow piston rod connected to saidpiston projecting through one end of said cylinder and fixedly connectedto said end wall, said piston rod having openings in its wallcommunicating with the cylinder on one side ofthe piston, a tube ofsmaller diameter within the bore of said piston rod and communicatingwith the opposite side of said ipiston, a plurality of fluid passages insaid casing and fluid tight connections between the bore of said pistonrod and said tube respectively and said passages.

8. In a device of the character described, the combination of amechanism to be adjusted, means for adjusting said mechanism comprisinga longitudinally adjustable memher. a casing inclosing said mechanismand said member, an adjusting cylinder attached to said member, saidcylinder being closed at each end, a piston in said cylinder, a hollowpiston rod connected to said piston projecting through one end of saidcylinder, said piston rod having openings 1n its well communicating withthe cylinder on one side of the piston, a tube of smaller diameterwithin the bore of said'ipiston rod and communicating with the oppositeside of said piston, a plurality of fluid passages in said casing andfluid tight connections between the bore of said piston rod and saidtube respectively and said passages, said connections comprising atapered extension on said piston rod, a tapered extension on said tubeprojecting beyond the end of said piston rod, correspondingly taperedsockets opening into said passages and means for drawing said piston rodagainst said casing and thereby compressing both said extensions intotheir respective sockets;

Signed at New York, in the county of New York and State of New York,this 13th day of June, 1914:.

CHARLES M. MANLY.

Witnesses:

A. I. MILLER, RUPERT E. RUNDELL.

